"People ask me how I do research for my science fiction. The answer is, I never do any research. I just enjoy reading the stuff, and some of it sticks in my mind and fits into the stories."
- Frederik Pohl

A person with extreme susceptibility to the greenhouse gas carbon dioxide.

In the near-future world of Earth, the excess carbon dioxide causes not only an increased greenhouse effect.

The crowds suddenly parted and more police hove into view, wrestling along a figure swaddled in restraint netting, who howled and writhed, wild-eyed, with face and clothes flecked in blood and spittle. A green gas cannister at his belt showed him to be a dozer - one of those unfortunates more affected by excess carbon dioxide than other people. In most, such borderline susceptibilities caused little more than sleepiness or headaches. But sometimes a wild mania resulted...